Abstract [en]

We present improved perturbative QCD (pQCD) predictions for Higgs boson hadroproduction at the LHC by applying the principle of maximum conformality (PMC), a procedure which resums the pQCD series using the renormalization group (RG), thereby eliminating the dependence of the predictions on the choice of the renormalization scheme while minimizing sensitivity to the initial choice of the renormalization scale. In previous pQCD predictions for Higgs boson hadroproduction, it has been conventional to assume that the renormalization scale mu(r) of the QCD coupling sigma(s)(mu(r)) is the Higgs mass and then to vary this choice over the range 1/2m(H) < mu(r) < 2m(H) in order to estimate the theory uncertainty. However, this error estimate is only sensitive to the nonconformal beta terms in the pQCD series, and thus it fails to correctly estimate the theory uncertainty in cases where a pQCD series has large higher-order contributions, as is the case for Higgs boson hadroproduction. Furthermore, this ad hoc choice of scale and range gives pQCD predictions which depend on the renormalization scheme being used, in contradiction to basic RG principles. In contrast, after applying the PMC, we obtain next-to-next-to-leading-order RG resummed pQCD predictions for Higgs boson hadroproduction which are renormalization-scheme independent and have minimal sensitivity to the choice of the initial renormalization scale. Taking m(H) = 125 GeV, the PMC predictions for the pp -> HX Higgs inclusive hadroproduction cross sections for various LHC center-of-mass energies are sigma(Incl vertical bar 7 TeV) = 21.21(-1.32)(+1.36) pb, sigma(Incl vertical bar 8 TeV) = 27.37(-1.59)(+1.65) pb, and sigma I-ncl vertical bar 13 TeV = 65.72(-3.01)(+3.46) pb. We also predict the fiducial cross section sigma fid(pp -> H -> gamma gamma): sigma(fid vertical bar 7 TeV) = 30.1(-2.2)(+2.3) fb, sigma(fid vertical bar 8 TeV) = 38.3(-2.8)(+2.9) fb, and sigma(fid vertical bar 13 TeV) = 85.8(-5.3)(+5.7) fb. The error limits in these predictions include the small residual high-order renormalization-scale dependence plus the uncertainty from the factorization scale. The PMC predictions show better agreement with the ATLAS measurements than the LHC Higgs Cross Section Working Group predictions which are based on conventional renormalization-scale setting.